"What these rules ultimately do is require any of the large emitters of carbon dioxide to come up with a plan to reduce their emissions back to 1990 levels," said Gary Gill, Deputy Health Director.

Environmentalist said the cap -- one of the most stringent in the nation -- is needed to combat the affects of global warming.

"Hawaii is really ground zero for change in climate, from sea level rise to shifting weather patterns so we really need to do our part here," said Jeff Mikulina, executive director of the Blue Planet Foundation.

Hawaii will join states like California and New Jersey which have place a hard cap on the amount of carbon emissions that refiners, energy companies and even landfill companies can emit into the air.

These new rules will require drastic emission reductions at state two largest producers of greenhouse gases: Hawaiian Electric Co. Kahe and Waiau power plants, which generate nearly 9 million tons of greenhouse gases each year.

"We're relying on turbines that are decades old and are some of the worst nationally in terms of the emissions produced," said Robert Harris, director of the Sierra Club's Hawaii Chapter.

Complying with this law could costs tens of millions of dollars and those expenses will likely be passed on to consumers.

"It is possible that we may have to make modifications to our generating units. That would increase our costs for generating electricity," said HECO spokesman Darren Pai.

The new rules may already be having an impact on Hawaii's gasoline market. Tesoro Hawaii, which announced that it is leaving the state earlier this month, said in November that the cap "places the future of our Kapolei refinery in question."

The new rules were supposed to be in place by the end of 2011 but could be finalized by summer.

From there, the state will begin monitoring emissions from Hawaii's 25 largest polluters and will eventually require them to produce a greenhouse gas reduction plan.